#!/bin/bash
#Check File to change. 
#By author rivers 2021-9-27
USERS="hbs"
while true
do
        echo "The Time is `date +%F-%T`"
        sleep 10
        NUM=`who|grep "$USERS"|wc -l`
        if [[ $NUM -ge 1 ]];then
                echo "The $USERS is login in system."
        fi
done